厦门市生态安全格局识别与生态管控区分级管控

生态控制区是防止城市建设无序蔓延,保障城市生态安全的重要生态空间。对城市生态控制区进行分级管控能够充分发挥其在维护城市生态安全,促进城市建设与生态保护协同发展等方面的作用。研究基于多源数据融合手段,采用"生态系统服务重要性-生态敏感性-景观连通性"评价结果识别生态源地,采用最小累积阻力模型（Minimum Cumulative Resistance,MCR）判定生态廊道和生态节点,形成了点-线-面交汇的生态安全格局网络,并将其应用于厦门市生态控制区分级划定。研究结果表明,厦门市生态源地共有17处,面积为604.19 km²,约占厦门市陆域面积的35.54%,包括陆域生态保护红线、水源保护地、森林公园等区域;提取主要生态廊道15条,长度为152.84 km,主要为连接生态源地与海洋的山海生态廊道;设置生态节点22个,主要为生态源地范围外的小面积重要保护区域和具有明确生态保护目标的区域。依据生态安全格局将厦门市生态控制区划分为三级管控区域,其中,生态源地、生态廊道以及生态节点划入一级管控区,面积占比为69.48%;一级管控区外的生态重要区和林地划入二级管控区,面积占比为10.15%;生态控制区内的其他区域划入三级管控区,面积占比为20.37%。在此基础上提出了分级管控建议,以期为厦门市实现生态控制区高水平保护与城市高质量发展提供重要参考和借鉴。     

红外相机技术在鼠类密度估算中的应用

2009年5月至2011年7月,在古田山国家自然保护区24 hm2(600 m×400 m)样地中用分层随机抽样法布置20台红外相机,监测样地内的鼠类密度.利用红外相机技术,引用物理学中气体分子碰撞率原理,在不对鼠类进行个体识别的情况下,估算样地内鼠类密度.结果表明,以此估算的样地内鼠类密度D3与标志重捕法估算的鼠类密度D之间不存在显著差异(P＞0.05),两者契合程度高,说明此模型具有相当高的精确性.而在较高的相机分布密度(0.83台/hm2)下得出的鼠类密度季节消长状况也验证了该模型的可靠程度.     

The RasGEF FgCdc25 regulates fungal development and virulence in Fusarium graminearum via cAMP and MAPK signalling pathways

Ras GTPases act as molecular switches to control various cellular processes by coupling integrated signals in eukaryotes. Activities of Ras GTPases are triggered by Ras GTPase guanine nucleotide exchange factors (RasGEFs) in general, whereas the role of RasGEF in plant pathogenic fungi is largely unknown. In this study, we characterized the only RasGEF protein in Fusarium graminearum, FgCdc25, by combining genetic, cytological and phenotypic strategies. FgCdc25 directly interacted with RasGTPase FgRas2, but not FgRas1, to regulate growth and sexual reproduction. Mutation of the FgCDC25 gene resulted in decreased toxisome formation and deoxynivalenol (DON) production, which was largely depended on cAMP signalling. In addition, FgCdc25 indirectly interacted with FgSte11 in FgSte11-Ste7-Gpmk1 cascade, and the ΔFgcdc25 strain totally abolished the formation of infection structures and was nonpathogenic in planta, which was partially recovered by addition of exogenous cAMP. In contrast, FgCdc25 directly interplayed with FgBck1 in FgBck1-MKK1-Mgv1 cascade to negatively control cell wall integrity. Collectively, these results suggest that FgCdc25 modulates cAMP and MAPK signalling pathways and further regulates fungal development, DON production and plant infection in F. graminearum.     

Effects and mechanisms of basic fibroblast growth factor on the proliferation and regenerative profiles of cryopreserved dental pulp stem cells

ObjectivesVarious factors could interfere the biological performance of DPSCs during post‐thawed process. Yet, little has been known about optimization of the recovery medium for DPSCs. Thus, our study aimed to explore the effects of adding recombinant bFGF on DPSCs after 3‐month cryopreservation as well as the underlying mechanisms.Materials and methodsDPSCs were extracted from impacted third molars and purified by MACS. The properties of CD146⁺ DPSCs (P3) were identified by CCK‐8 and flow cytometry. After cryopreservation for 3 months, recovered DPSCs (P4) were immediately supplied with a series of bFGF and analysed cellular proliferation by CCK‐8. Then, the optimal dosage of bFGF was determined to further identify apoptosis and TRPC1 channel through Western blot. The succeeding passage (P5) from bFGF pre‐treated DPSCs was cultivated in bFGF‐free culture medium, cellular proliferation and stemness were verified, and pluripotency was analysed by neurogenic, osteogenic and adipogenic differentiation.ResultsIt is found that adding 20 ng/mL bFGF in culture medium could significantly promote the proliferation of freshly thawed DPSCs (P4) through suppressing apoptosis, activating ERK pathway and up‐regulating TRPC1. Such proliferative superiority could be inherited to the succeeding passage (P5) from bFGF pre‐stimulated DPSCs, meanwhile, stemness and pluripotency have not been compromised.ConclusionsThis study illustrated a safe and feasible cell culture technique to rapidly amplify post‐thawed DPSCs with robust regenerative potency, which brightening the future of stem cells banking and tissue engineering.     

Efficiency of algalization of rice in the Nile Delta with different amounts of nitrogen and potassium fertilization

Indica rice var. IR 28 was inoculated with cyanobacteria (blue-green algae) together with elther 0,72 and 144 kg N/ha or 0,60 and 120 kg K₂O/ha. Plant performance, yield, nitrogen contents and chemical fertilizer-N-use efficiency positively responded to inoculation with the cyanobacteria and increased further with increasing amounts of both N and K. Effects arising from the cyanobacteria, N or K differed under the other two factors.     

Genome-wide analysis of pseudogenes reveals HBBP1’s human-specific essentiality in erythropoiesis and implication in β-thalassemia

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